Question

A dog owner records the weight of her dog. She finds that from the age of 20 weeks to the age of 48 weeks, the dog’s weight can be modelled by the equation w = 0.92t−0.15 (20 ≤ t ≤ 48),

Explain why the model cannot be extended to model accurately the dog’s weight at birth

Answer 1

See explanation

Explanation:

A dog owner records the weight of her dog. She finds that from the age of 20 weeks to the age of 48 weeks, the dog’s weight can be modelled by the equation

`w = 0.92t-0.15\ \ \ (20\le t\le 48)`

where

w = weight

t = number of week from 20 weeks to 48 weeks

If we want to extend this model to the dog's weight at birth, then find the dog's weigth when it was born.

At t = 0,

`w=0.92\cdot 0-0.15\\ \\w=-0.15\ kg`

We get the dog's weight -0.15 kilograms at the day the dog was born. But this is impossible, because the dog's weight cannot be negative.